"My little cowboy turned four today!! such an awesome day!" Tennessee-based Bookout, 21, tweeted on her son's big day, posting a pic of him dressed up in an adorable checkered shirt, straw hat and red bandana. "He is my perfect world."
On the agenda for Bentley's big bash: Horse rides, a petting zoo, and -- breaking with the cowboy theme -- a motorcross-inspired birthday cake!
Welcoming Bentley in 2008 with ex Edwards, Bookout calls her son's birthday celebrations one of the toughest times to be a single mom, because she has to share custody of him with his dad.